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A balloon rises because it is filled with a gas that is lighter than air. Humans have always dreamed of flying through the air. The dream came true in 1783 when a hot-air balloon carried its first passengers.
The lightest gas is hydrogen. Hydrogen, however, catches fire and explodes easily. Coal gas produced when coal is heated without air is cheaper, but it is heavier than hydrogen and also a fire hazard. Helium, almost as light as hydrogen, does not burn. Although scarce and expensive, it is the ideal balloon gas.
A hot air balloon can be controlled by the force of heat which makes the balloon fly.To land the hot air balloon there is a cord that they pull and a little parachute will go up letting some of the hot air out which makes it land.
It uses the speed and direction in which the wind travels to move Pilots place the balloon at different altitudes at certain times in the flight to change the direction of the flight path.
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